Regular Expressions 101

Save & Share

  • Regex Version: ver. 2
  • Update Regex
    ctrl+⇧+s
  • Save new Regex
    ctrl+s
  • Add to Community Library

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests

Tools

Sponsors
There are currently no sponsors. Become a sponsor today!
An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
No Match

r"
"

Test String

Substitution

Processing...

Code Generator

Language

Generated Code

# coding=utf8 # the above tag defines encoding for this document and is for Python 2.x compatibility import re regex = r"(?m)^DOCUMENTATION.*(\"{3}|'{3})\n-*\n?([\s\S]+?)^\1[\s\S]*" test_str = ("#!/usr/bin/python\n" "# -*- coding: utf-8 -*-\n\n" "# (c) 2014, Ramon de la Fuente <ramon@delafuente.nl>\n" "#\n" "# This file is part of Ansible\n" "#\n" "# Ansible is free software: you can redistribute it and/or modify\n" "# it under the terms of the GNU General Public License as published by\n" "# the Free Software Foundation, either version 3 of the License, or\n" "# (at your option) any later version.\n" "#\n" "# Ansible is distributed in the hope that it will be useful,\n" "# but WITHOUT ANY WARRANTY; without even the implied warranty of\n" "# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the\n" "# GNU General Public License for more details.\n" "#\n" "# You should have received a copy of the GNU General Public License\n" "# along with Ansible. If not, see <http://www.gnu.org/licenses/>.\n\n" "DOCUMENTATION = \"\"\"\n" "module: slack\n" "short_description: Send Slack notifications\n" "description:\n" " - The M(slack) module sends notifications to U(http://slack.com) via the Incoming WebHook integration\n" "version_added: 1.6\n" "author: Ramon de la Fuente <ramon@delafuente.nl>\n" "options:\n" " domain:\n" " description:\n" " - Slack (sub)domain for your environment without protocol.\n" " (i.e. C(future500.slack.com))\n" " required: true\n" " token:\n" " description:\n" " - Slack integration token\n" " required: true\n" " msg:\n" " description:\n" " - Message to send.\n" " required: true\n" " channel:\n" " description:\n" " - Channel to send the message to. If absent, the message goes to the channel selected for the I(token).\n" " required: false\n" " username:\n" " description:\n" " - This is the sender of the message.\n" " required: false\n" " default: ansible\n" " icon_url:\n" " description:\n" " - Url for the message sender's icon (default C(http://www.ansible.com/favicon.ico))\n" " required: false\n" " icon_emoji:\n" " description:\n" " - Emoji for the message sender. See Slack documentation for options.\n" " (if I(icon_emoji) is set, I(icon_url) will not be used)\n" " required: false\n" " link_names:\n" " description:\n" " - Automatically create links for channels and usernames in I(msg).\n" " required: false\n" " default: 1\n" " choices:\n" " - 1\n" " - 0\n" " parse:\n" " description:\n" " - Setting for the message parser at Slack\n" " required: false\n" " choices:\n" " - 'full'\n" " - 'none'\n" " validate_certs:\n" " description:\n" " - If C(no), SSL certificates will not be validated. This should only be used\n" " on personally controlled sites using self-signed certificates.\n" " required: false\n" " default: 'yes'\n" " choices:\n" " - 'yes'\n" " - 'no'\n" "\"\"\"\n\n" "EXAMPLES = \"\"\"\n" "- name: Send notification message via Slack\n" " local_action:\n" " module: slack\n" " domain: future500.slack.com\n" " token: thetokengeneratedbyslack\n" " msg: \"{{ inventory_hostname }} completed\"\n\n" "- name: Send notification message via Slack all options\n" " local_action:\n" " module: slack\n" " domain: future500.slack.com\n" " token: thetokengeneratedbyslack\n" " msg: \"{{ inventory_hostname }} completed\"\n" " channel: \"#ansible\"\n" " username: \"Ansible on {{ inventory_hostname }}\"\n" " icon_url: \"http://www.example.com/some-image-file.png\"\n" " link_names: 0\n" " parse: 'none'\n\n" "\"\"\"\n\n\n" "SLACK_INCOMING_WEBHOOK = 'https://%s/services/hooks/incoming-webhook?token=%s'\n\n" "def build_payload_for_slack(module, text, channel, username, icon_url, icon_emoji, link_names, parse):\n" " payload = dict(text=text)\n\n" " if channel is not None:\n" " payload['channel'] = channel if (channel[0] == '#') else '#'+channel\n" " if username is not None:\n" " payload['username'] = username\n" " if icon_emoji is not None:\n" " payload['icon_emoji'] = icon_emoji\n" " else:\n" " payload['icon_url'] = icon_url\n" " if link_names is not None:\n" " payload['link_names'] = link_names\n" " if parse is not None:\n" " payload['parse'] = parse\n\n" " payload=\"payload=\" + module.jsonify(payload)\n" " return payload\n\n" "def do_notify_slack(module, domain, token, payload):\n" " slack_incoming_webhook = SLACK_INCOMING_WEBHOOK % (domain, token)\n\n" " response, info = fetch_url(module, slack_incoming_webhook, data=payload)\n" " if info['status'] != 200:\n" " obscured_incoming_webhook = SLACK_INCOMING_WEBHOOK % (domain, '[obscured]')\n" " module.fail_json(msg=\" failed to send %s to %s: %s\" % (payload, obscured_incoming_webhook, info['msg']))\n\n" "def main():\n" " module = AnsibleModule(\n" " argument_spec = dict(\n" " domain = dict(type='str', required=True),\n" " token = dict(type='str', required=True),\n" " msg = dict(type='str', required=True),\n" " channel = dict(type='str', default=None),\n" " username = dict(type='str', default='Ansible'),\n" " icon_url = dict(type='str', default='http://www.ansible.com/favicon.ico'),\n" " icon_emoji = dict(type='str', default=None),\n" " link_names = dict(type='int', default=1, choices=[0,1]),\n" " parse = dict(type='str', default=None, choices=['none', 'full']),\n\n" " validate_certs = dict(default='yes', type='bool'),\n" " )\n" " )\n\n" " domain = module.params['domain']\n" " token = module.params['token']\n" " text = module.params['msg']\n" " channel = module.params['channel']\n" " username = module.params['username']\n" " icon_url = module.params['icon_url']\n" " icon_emoji = module.params['icon_emoji']\n" " link_names = module.params['link_names']\n" " parse = module.params['parse']\n\n" " payload = build_payload_for_slack(module, text, channel, username, icon_url, icon_emoji, link_names, parse)\n" " do_notify_slack(module, domain, token, payload)\n\n" " module.exit_json(msg=\"OK\")\n\n" "# import module snippets\n" "from ansible.module_utils.basic import *\n" "from ansible.module_utils.urls import *\n" "main()") subst = "---\\n\\3" # You can manually specify the number of replacements by changing the 4th argument result = re.sub(regex, subst, test_str, 1) if result: print (result) # Note: for Python 2.7 compatibility, use ur"" to prefix the regex and u"" to prefix the test string and substitution.

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Python, please visit: https://docs.python.org/3/library/re.html